Electric rare gas lighting tube



Aug .27,1940. A, LE ERER' v I 2,213,483

ELECTRIC RARE GAS LIGHTING TUBE Original File d Nov] 20, 1930 INVENTOR Anion L edever' BY %w/ ATTORNEY Patented Aug. 27, 1940 PATENT OFFICE 2,213,183 ELECTRIC RARE GAS LIGHTING TUBE Anto'n Lederer, Vienna,

Austria; Catherine Da'nzer and General Conrad Randa, executors of said Anton Lederer, deceased, assignors, by mesne assignments, to General Electric Company, a corporation of New York Application November 20, 1930, Serial No. 497,025.

Renewed October 20, 1939.

her 4, 1929 In Austria Decem- 3 Claims. (01. 176-122) My prior patent application No. 468,884, filed July 18, 1930, to which reference is made as an aid to an understanding of the present invention, covers an electric rare gas lighting tube with hot electrodes characterized by the fact that I the mutual d stance and the arrangement of the electrodes'and the shape and dimensions of the glass bulb are such that the light phenomena caused by the discharge extend over the whole I. grflgearly the whole space of the largest possible It was shown in said prior application that the light phenomenon at the discharge appears in such a manner as to form an intense aureole around each of the hot electrodes while the remaining parts of the gas filling show a weaker lighting, decreasing with the distance from the electrodes. If it is desired to have the total space of the bulb lighted visibly it is necessary to se- 9) lect for a given voltage and a given nature of the electrodes, the variable dimensions and shapes of the tube in a definite manner.

I- have found that the effect of the full lighting" of such a tube with two hot electrodes for 25 operation on alternate currents may be attained also if the distance between the two electrodes is made so small that the two aureoles forming around the two electrodes combine into a single aureole.

80 In this case also, the dimensions and the shape of the bulb can be selected in such a. manner that the total space of the bulb around the common aureole of the two electrodes lights visibly, although with less intensity than the aureole it- 36 self.

If, for instance, a globe shaped lighting tube contains a mixture of neon and helium (about 99% neon and 1% helium) at a pressure of 1 to 2 mm. and the distance of the. electrodes from 40 each other is 2 to 5 mm. a single aureole is formed around the two electrodes; and if the diameter of the globe shaped bulb is 120 to 150 mm., the total space of the bulbs will light visibly. If on the other hand the distance between the 45 electrodes is increased to about 12 mm. the

aureole begins todiyide.

In the accompanying drawing are the elec trodes which may be about mm. apart, m is the support of the electrodes c, a represents the 50 aureole and r the limit of the luminescent gases.

By suflicient heating of the electrodes 0 an are .or continuous luminous gaseous discharge is produced and aureoles develop around the electrodes. These aureoles', however, combine into a 65 single aureole a whereby a particularly beautiful effect is obtained, and also the gas surrounding this aureole has an intense luminosity which gradually decreases in intensity to the limit or outer boundary 1" of the luminous zone.

By proper selection of the dimensions of the glass bulb it may be achieved that the bulb is almost completely filled by the luminescent gas.

The tube, which may be provided with an ordinary. lamp base, can easily be screwed in the customary fixtures and be operated on the ordinary main supply of 110 volts or less.

I claim:

1. Anelectric illuminating lamp for operation on alternating current, comprising a bulb of from 120 to 150 mm. diameter, two co-oper- 15 ating electrodes of substantially equal size lo-- cated centrally therein at not less than 2 mm. and not more than 12 mm. apart each of which is capable of emitting electrons freely when heated, means for causing each electrode to be raised to gg the required temperature and for applying a potential between said electrodes, and rare gas at about from 1' to 2 mm. pressure within said bulb,

whereby, with an inter-electrode potential applied by the electrodes a continuous luminous gaseous cathodic discharge will be produced which appears as a single bright core surrounding both electrodes and enclosed by a luminous zone gradually decreasing in intensity to its outer boundary. 2. An electric illuminating lamp for operation on alternating current, comprising a bulb of not less than 120 mm. and not more than 150 mm.- diameter, two co-operating electrodes of substantially equal size located centrally therein at not less than 2 mm. and not more than 12 mm.- apart each of which is capable of emitting electrons freely when heated, means for causing each electrode to be rais d to'the required temperature and for applying a potential between said 40 electrodes, and rarifiedneon gas within said bulb at a pressure sufiicientlylow in relation to said inter-electrode spacing that with an inter,- electrode potential applied by the electrodes a continuous luminous gaseous discharge will be produced which appears as a single bright core surrounding both electrodes and enclosed by a luminous zone gradually decreasing in intensity to its outer boundary.

3. An electric illuminating lamp for operation on alternating current, comprising a bulb of between and mm. diameter, two cofoperat ing electrodes of substantially equal size located centrally therein at from about 2 to 5 mm.- apart,

each of which is capable of emitting electrons 55 freely when heated, means for causing each electrode to be raised to the required temperature and for applying a potential between said electrodes, and a mixture of 99% neon and 1% helium within said bulb at from about 1 to 2 mm.

pressure, whereby, with an inter-electrode potential applied by the electrodes a continuous lumi- 

